I am thinking that my heater control valve might be why I'm not gett ing any heat. It has 3 hoses about an inch or so in diameter and a smaller one that is maybe a vacuum or runs inside the car. I know it goes to a wirebundle next to the firewall. What are the other 3 hoses. One runs into the back of the intake one runs to a metal pipe that runs to the radiator and the third one I think goes back the the heater core?

What exactky are they and what do they do and does the heater control valve usually go or is it rebuildable?

Any help would be appreciated. Scoty

 

asked and answered

I'm pretty sure my hcv is bad. I can't feel it pulling in vacuum when I take the vacuum hose off so I'm assuming that is the problem. I am going to try and get one tomorrow.
Scoty

 

ummmmm, it doesnt pull vac, it recieves vac from the heater control head inside the car, it is so when you select anythong other than heat, it stops coolant flow through the core and reroutes it back to the rad

 

Thanks Dave,

This HCV thingie really has me confused when I switch it to heat should I feel anything on the hose if it is unconnected?

 

i think you should only feel vac on the line in the positions other than heat, so the default(no vac/vac leak) is heat

 

New HCV, flush radiator and a new heater core last year. I know the heater was working a few months ago, I had a overheating problem and would turn the heater on in traffic to help keep the motor cool. Now as winter is approaching it doesn't want to blow any hot air.

When i swith from cold to hot on my control panel I can hear a chang in pitch, but it just isn't getting hot. I have felt the hoses and they are warm and coolant is circulating, for I no longer have any overheating problems, I did change the radiator and that solved the overheating problem. It also has a new thermostat, also.

This is really starting to aggravate me. Any ideas!!

Scoty

 

i've saw several f bodys leak vacuum at the dial selector with all the lines going to it. way i check it is to run some very low presure, like 3-4 psi, air into the vacuum line at the heater control valve and soap the system and look for bubbles

 

So it is blowing air inside the car right? just not hot air?

If thats the case the vacuum line could be bad or the valve itself could be bad.

If no air at all is coming inside the car it is probably the blower motor.

 

Time to update:

I just changed the heater core. I still am not gettting any heat in the car. Yes it is blowing air just not warm air. When pulling the core out I noticed that the coolant inside of it was mostly water and very brown....pre-flushing the radiator. Way back in the summer I was having some problems with coolant leaks and was just using water.

So after pulling the heater core out I would say that there is no coolant running through the core. That leads me to believe that the vacuum line is bad somewhere. Is it possible that I can bypass the hcv and reroute the heater hoses.

This stupid car just has to last me the winter as the rest of it has many issues.

I am going to try and go around the HCV by connecting the heater hoses back to the radiator.

Any thoughts on this would be greatly appreciated.
Scoty